Govia Thameslink admits the seats on the new Class 700 trains are considerably firmer than older designs. The seats have limited padding, because cushioning is deemed as a fire hazard by the Department for Transport (DfT), according to the rail operator.

They also have to be made from graffiti-proof material, which the DfT said has a "firm feel".

Travellers have complained the seats are hard and narrow,

We have no view on how hard and narrow train seats should be. Nor, in fact, about how flammable or graffiti resistant they should be. But then that's rather our point. That we don't know leads us to a reasonable conviction that the regulators don't either.

For said regulators are going to regulate to fit their sole aim. Those commissioned with preventing fire alone will insist upon something that just doesn't burn, those against teenage scribbling ditto. Rather lost in such concerns will be the purpose of the enterprise, producing something which passengers desire to sit upon. The complexity, the balance between differing desires, will be lost in a purely regulatory world.

Which is what is happening here. The provider of the service, varied places for posteriors, isn't allowed to make that trade off which they are best placed to make, between their needs and desires and those of their customers. Someone, even many people, from outside that knowledgeable group are able to insist upon their own designs. Which is why we end up with seats which don't burn but which aren't worth sitting upon.

Which is where our own view comes back into play. We do have a vision of regulation and one which does work. Owing very much more to the Common Law principles than this sort of level of detail. General principles - don't kill the customers, don't poison them etc - using post facto enforcement and design revision. And let the people who know, that interface of consumer and producer, then get on with things.